Backbone: Are Views really Controllers?

Question

I\'m building my first Backbone.js app and I\'m confused about how much responsibility I\'m supposed to give to or hide from my Views.

In my example, I\'m building

Answer 1

Your understanding of the architecture is correct. Backbone does not recognize the concept of a "controller" in the traditional MVC sense. (In fact, Backbone used to actually have an object called a Controller, but it has been renamed Router to more accurately describe what it does.)

The functions you list (drag-drop, delete rows, sorting, etc.) would all belong in a View. A view describes what you see and responds to user input. Anything involving an event (a click, a keypress, a submit, etc.) all go inside of a view. But your view should never actually manipulate the data; that should be done by its model. You are correct in thinking that a view acts like a controller, because it packages data and sends it to the model, which will then validate/set/save appropriately. Once those actions have occurred, the view re-renders itself to represent the new version of the data inside the model.

One note of caution: your view should not be too strenuously tied to the DOM. It is Backbone convention to have a top-level DOM element that your view is tied to (e.g., a form or a div) and then deal only with its sub-elements. That is appropriate; in general, things like "remove this link from this div" inside your view are not. If you find your view growing unwieldy, you most likely need to break it into subviews, each with their respective behaviors as components of their whole.